Fix regexp to allow multiple digits in Mac OS minor version.
Fix regexp to allow multiple digits in Mac OS minor version.

The regular expression check for the -mmacosx-version-min value only
looked at a single digit in the minor version number, so it did not
compare correctly if the option was setting the minimum version
to (say) 10.11.

claui/brew,konqui/brew,mahori/brew,EricFromCanada/brew,claui/brew,claui/brew,EricFromCanada/brew,EricFromCanada/brew,vitorgalvao/brew,EricFromCanada/brew,vitorgalvao/brew,reitermarkus/brew,sjackman/homebrew,Homebrew/brew,nandub/brew,MikeMcQuaid/brew,JCount/brew,claui/brew,MikeMcQuaid/brew,reitermarkus/brew,vitorgalvao/brew,mahori/brew,reitermarkus/brew,konqui/brew,konqui/brew,sjackman/homebrew,sjackman/homebrew,MikeMcQuaid/brew,Homebrew/brew,MikeMcQuaid/brew,JCount/brew,vitorgalvao/brew,nandub/brew,Homebrew/brew,konqui/brew,nandub/brew,mahori/brew,JCount/brew,JCount/brew,mahori/brew,nandub/brew,reitermarkus/brew,sjackman/homebrew,Homebrew/brew